1. Field of the Invention
The present invention relates to a fixing device for fixing an image on a recording material used in an image forming apparatus, such as an electrophotographic apparatus or an electrostatic recording apparatus.
2. Description of the Related Art
In recent years, heat roller fixing devices have been widely used as the fixing device used in an image forming apparatus.
To separate the recording material from a roller, the heat roller fixing device is generally provided with a plurality of separating claws.
The heat roller fixing device may be provided with a separation guide which is not in contact with the roller, as shown in FIG. 12.
In the fixing device shown in FIG. 12, a pressure roller 3 is pressed against a fixing roller 2 by a pressurizing means (not shown) to form a nip having a predetermined width. Fixing roller bearings 18 support the two end portions of the fixing roller 2. The fixing roller bearings 18 are disposed outside of a recording material passage area. A separation guide 10 is spaced from the fixing roller 2 by a predetermined interval and extends over the entire area of the fixing roller in the longitudinal direction thereof (in a direction perpendicular to the surface of the recording material).
Where the separation claws are provided, the number of parts required for the fixing device is increased.
Furthermore, both the adjustment of the contact force of the separation claws to the roller, and arrangement thereof are difficult. However, if they are not properly done, the separation claws may damage the surface of the roller.
Where the separation guide is used, a gap by which the separation guide is spaced from the fixing roller may vary depending on the variations in the components. If the gap is too large, separation failure may occur, causing jam of the recording material.